France has launched air strikes against Islamic State (IS) militants in their Syrian stronghold of Raqqa, while a manhunt continues for a man thought to have helped organize the Paris terrorist attacks.

The French Defense Ministry said in a statement on November 15 that French warplanes dropped 20 bombs in Raqqa, destroying a munitions depot and a militant training camp.

French Foreign Minister Laurent Fabius, speaking on the sidelines of the G20 summit in Turkey, said France was reacting in self-defense.

"We can't let Daesh attack without a reaction," said Fabius, using an alternative name for the IS group.

The Syrian Observatory for Human Rights, a London-based monitoring group, said no casualties had been reported.

The air strikes came after the attacks in Paris in which at least 132 people were killed some 350 were injured in the deadliest terrorist attack in Europe since the 2004 Madrid bombings.

French President Francois Hollande called the attacks an "act of war" and promised a "ruthless" response against the IS group, which claimed responsibility.

French police have issued an international arrest warant for a man they believe might have helped organize the deadly assaults with two of his brothers in Belgium.

Police said they were seeking a Belgian-born man, Abdeslam Salah, in connection with the attack, describing him as "dangerous."

French police issued a photo of the suspect on November 15 after police in Belgium issued the arrest warant.

"The abject attacks that hit us on Friday were prepared abroad and mobilized a team in Belgium that benefited...from help in France," French Interior Minister Bernard Cazeneuve told reporters after meeting his Belgian counterpart in Paris.

Belgian officials said they had arrested seven people in Brussels after two Belgian-registered cars were discovered in Paris, both suspected of being used by the attackers.

"I do not want any preachers of hatred on Belgian soil! There is no place for them in Belgium," Belgian Prime Minister Charles Michel said on Twitter.

Abdeslan Salah

A judicial source said Salah, a 26-year-old French national, had rented one of the two cars, a Volkswagen Polo, that was found not far from the Bataclan concert hall, the site of the bloodiest attack.

Only one of the attackers has been named -- Ismael Omar Mostefai, a 29-year-old who lived in the city of Chartres, southwest of Paris.

He was identified by the print from one of his fingers that was severed when his suicide vest exploded.

German officials said a man arrested in the southern state of Bavaria earlier this month after guns and explosives were found in his car may also be linked to the attacks.

The Serbian Interior Ministry said the holder of a Syrian passport found next to the body of one of the attackers outside the Stade de France stadium "was registered on the Presevo border crossing on October 7 this year, where he formally sought asylum." The Presevo border crossing separates Serbia from Macedonia.

Greek authorities had confirmed that the document had been used to travel through the island of Leros on October 3.

WATCH: Migrants and refugees arriving at the Macedonian-Serbian border crossing of Tabanovce were horrified to learn of the November 13 terrorist attacks in Paris. As they travel through Europe, they now fear becoming targets of a backlash and worry it will become harder to claim asylum.

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Hollande has imposed a state of emergency and canceled his plans to attend the G20 summit in Turkey on November 15.

A special service for the families of the victims and survivors will be held at Paris's Notre Dame Cathedral.

Luxembourg, which currently holds the European Union’s rotating presidency, announced that EU interior ministers would meet on November 20, saying the emergency talks would “strengthen the European response” to the attacks.

Speaking on November 15 in Turkey, where he arrived for a G20 summit, U.S. President Barack Obama described the assaults as "an attack on the civilized world" and said the United States would work with France to hunt down those responsible.

Meanwhile, the head of the world's top Islamic body condemned "in the strictest terms" the Paris gun and bomb attacks and called for “a concerted joint action to combat the scourge of terrorism which has become the arch enemy of humanity at large."

Iyad Madani, the secretary-general of the Jeddah-based Organization of Islamic Cooperation, voiced his "firm rejection of any terrorist act" that undermines "universal human values including the values of freedom and equality that France has consistently promoted."